The present application relates to a connector thermally insulating protective sleeve, in particular a connector thermally insulating protective sleeve connected to a urea solution supply pump.
Selective catalytic reduction after-treatment systems are already widely used in diesel engines at the present time, due to legislation and environmental protection requirements. Such a selective catalytic reduction after-treatment system comprises a urea solution supply pump, connected via a connecting pipeline to a nozzle for injecting urea solution into an exhaust gas treatment mixing apparatus.
Generally, in order to facilitate installation and post-maintenance, such a urea solution supply pump is in direct contact with the outside air after being installed in place. The connecting pipeline is detachably connected to an outlet of the urea solution supply pump by means of a connector.
The connecting pipeline itself may be an electrically heated pipe, in order to be electrically heated to prevent freezing of feed liquid in the pipeline when the air temperature is especially low in winter. The urea solution supply pump itself is also provided with a self-heated thawing apparatus. However, the region where the connector is connected to the outlet generally has no electrically heated means of protection; hence, when the air temperature is especially low in winter and the diesel engine has been switched off for a long period of time, urea solution in the connector and/or outlet freezes, and if the engine is started again, such frozen urea is very difficult to melt quickly. Thus delivery of urea solution from the supply pump is affected, and this in turn has an impact on the exhaust gas treatment effect of the selective catalytic reduction after-treatment system.
Furthermore, other liquid feed apparatuses in which connection ports are exposed to the outside also have similar problems.